Field of the Invention
The present invention relates to thermal insulation and more particularly to a system of solid or flexible insulation pieces that are thermodynamically balanced.
Description of the Prior Art
It is well-known in the art to use a dead air space to insulate. This works because air is a very poor thermal conductor. However, a totally dead air space covering or surrounding an item to be insulated does not allow the item to breathe. This can result in moisture buildup with undesirable consequences. Hence, most building insulation is made from a large number of small fibers woven or packed together. Fiber glass insulation is an example of this. The tightly woven glass fibers provide a precarious path for air molecules and hence form an air space that only allows very slow breathing. However, Insulation like fiberglass and many others are difficult to handle, many times causing itching or allergic reactions in workers. The powder or fibers are also dangerous to breathe. In addition, insulation bats like fiberglass compress and will not support weight. Powdered or chunk insulation in attics and other locations suffer from the same problem. They will not support much weight, and they create dust when handled. Hence it is difficult to store items in such attics, and it is very difficult to walk since one can only step on joists.
What is needed is insulation that contains an almost dead air space; however, an air space that allows slow breathing by using offset openings on opposite sides of panels to prevent moisture buildup on lower surfaces.
All insulation has thermal losses, including totally dead air spaces. The major causes of thermal loss of an insulated object are 1) thermal conduction, 2) radiation, and 3) convective cooling. If the object is in direct contact with only air, loss by thermal conduction is small. Also, at the low temperatures encountered in insulating structures, radiation loss is also small. However, if the air can move past the object, convective cooling causes major losses. The purpose of almost all building insulation is to minimize convective cooling. A dead air space or almost dead air space accomplishes this.
It is well-known that the rate of convective cooling is proportional to object temperature, the air temperature, and most predominately, the rate of airflow past the surface of the object. It is the latter parameter that a dead air space or almost dead air space minimizes. Air is only allowed to defuse into and out of the almost dead air space, and hence the rate of airflow is very small near the surface of the object. This leads to very low values of convective cooling.
It would be very advantageous to have a thermal insulation technology that operates on the principle of an almost dead air space that is allowed to breathe by diffusion, but has openings on opposite sides of panels or sheets offset from one-another, and that is rigid enough to support stored weight or to be walked upon.